Receiver not registered in SyncTask$ConnectivityChangeReceiver persists in firebase-messaging 25.0.1 on Android 16

Hi Firebase team,

We are still seeing the same crash reported in this issue after applying the fix
released with BoM 30.11.0.

Environment:
- Firebase Messaging resolved version: 25.0.1
- FlutterFire firebase_messaging: 16.0.4
- targetSdkVersion: 36
- App version: 1.9.30 (10930)

Crash:
java.lang.RuntimeException: Error receiving broadcast Intent
Caused by: java.lang.IllegalArgumentException: Receiver not registered:
com.google.firebase.messaging.SyncTask$ConnectivityChangeReceiver
at android.app.LoadedApk.forgetReceiverDispatcher(...)
at android.app.ContextImpl.unregisterReceiver(...)
at android.content.ContextWrapper.unregisterReceiver(...)
at com.google.firebase.messaging.SyncTask$ConnectivityChangeReceiver.onReceive(...)

We verified that firebase-messaging 25.0.1 already contains the receiverContext
change introduced by the fix for this issue. The crash still occurs at:

receiverContext.unregisterReceiver(this)

Crashlytics data for this release:
- 52 crash events
- 100% occurred while the app was in the background
- 79% on Android 16
- 65% on Samsung devices

We also checked firebase-messaging 25.1.3 and the receiver is still unregistered
without handling IllegalArgumentException.

Could you please reopen this issue and advise whether there is a known Android 16 /
Samsung-specific cause, a further fix, or an officially supported workaround?

Thank you.

Start by inspecting SyncTask$ConnectivityChangeReceiver, especially the receiverContext.unregisterReceiver(this) call, and compare firebase-messaging 25.0.1 with 25.1.3. Reproduce the background crash on Android 16, particularly on Samsung devices, using the reported target SDK and dependency versions. Done means identifying the cause and providing a verified fix or officially supported workaround.

Written by the indexing model from the issue text.